Joos vs 77.Z
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Joos
Never worry about a dead phone again. This app helps you find nearby charging stations to power up your device on the go. Simply scan a QR code, charge, and return the device at your convenience.
- Find nearby charging stations
- Scan QR code to rent
- Charge on the move
- Flexible return options
- Discover promotions
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Joos Power provides the ultimate solution to your phone running out of battery whilst you’re on the move. The service is simple; find your nearest station, scan the QR code, charge on the move, and return at a time and place convenient for you – all through our easy-to-use app. Download today and never worry about a dead phone ruining your day again & discover all sorts of promotions and added extras
77.Z
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77.Z is a high-performance power bank designed to provide reliable power for your electronic devices anytime and anywhere. With advanced fast-charging technology and a built-in safety protection system, it is compatible with smartphones, tablets, and other electronic devices. With its high-capacity battery, 77.Z ensures multiple device charges throughout the day. Its compact and lightweight design makes it easy to carry, whether you are traveling, working, or going about your daily routine. 77.Z is the perfect choice to keep your devices powered.
Screenshots
Verdict
Joos and 77.Z are too close to call on the numbers: across 6 compared parameters — price, update cadence, ads and in-app purchases among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
Both ship on a similar rhythm, roughly every 3 weeks. The most recent releases landed on October 19, 2026 and October 8, 2026 respectively.
| Parameter | Joos | 77.Z |
|---|---|---|
| Price | Free | Free |
| Rating | 4.5 (27 ratings) — better | — |
| Positive reviews | 50.0% of reviews | — |
| Number of ratings | 27 — better | — |
| Update frequency | Every 3 weeks | Every 3 weeks |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free with in-app purchases | — |
| Devices | iPhone, iPod | iPhone, iPod |
| Requires iOS | 15.0 — better | 15.1 |
| Further details — not scored | ||
| Size | 54 MB | 35 MB |
| Age rating | 4+ | 17+ |
| Developer | Silcs Solutions Ltd | IoT (Shenzhen) Sharing Technology Co., Ltd |
Bugs and requests
Joos
Reported bugs
14 issues- Charger lead faulty
- Return didn't work properly
- First battery did not charge
- Power bank did not charge phone
- Machine took money but didn't work
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- Chargers not working
- Charged as if not returned
- Power bank ran out of charge quickly
- Power bank didn't charge phone
- No charge in the power bank
- Charger cable needs to be pushed
- App requires internet and battery to sign up
- Map not accurate for station locations
- Charging ports everywhere now
Requested features
7 requests- Improve charging speed
- Offer better value for money
- Provide an exchange option for faulty cables
- Make pricing clearer in the app
- Support fast charging
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- Make charging stations more available
- Invest in better quality power banks
77.Z
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Joos
No in-app purchases
77.Z
No in-app purchases
